The tumoricidal activity of the murine monoclonal antibody 17-1A has been characterized in the nude mouse and in humans. See, e.g., Herlyn, D. and Koprowski, H. (1982) xe2x80x9cIgG2a Monoclonal Antibodies Inhibit Human Tumor Growth Through Interaction with Effector Cellsxe2x80x9d Proc. Natl Acad. Sci. USA 79, 4761-4765. Several cases have been reported where the administration of Mab 17-1A resulted in a partial or complete regression of metastatic colorectal or pancreatic carinomas. See Sears, H. F. et al. (1984) xe2x80x9cEffects of monoclonal antibody immunotherapy on patients with gastrointestinal adenocarcinoma.xe2x80x9d J. Biol. Resp. Mod. 3, 138-150; Sears, H. F., et al., xe2x80x9cPhase II Clinical Trial of a Murine Monoclonal Antibody Cytotixic for Gastrointestinal Adenocarcinomaxe2x80x9d (1985) Cancer Res. 45: 5910-5913. Generally, the antibody has been administered as single administration of 500 xcexcg or less.
This invention pertains to a method of immunotherapy of gastrointestinal tumors employing multiple, high doses of murine monoclonal antibody against the gastrointestinal tumor-associated antigen 17-1A. The method comprises administering to a patient afflicted with gastrointestinal tumor, murine monoclonal antibody against the antigen 17-1A in multiple, sequential doses of about 100 mg or more for a total overall dose of from about 0.1 to about 5 grams. Each dose of the murine antibody can be administered at one to three day intervals up to weekly intervals to achieve and maintain a xe2x80x9ccontinuousxe2x80x9d high level of circulating antibody. Mixtures (xe2x80x9ccocktailsxe2x80x9d) of two or more murine anti-17-1A antibodies can be given. The multiple, high dose therapy can be performed as adjuvant therapy to chemotherapy, radiotherapy or surgery.
The high dose murine antibody therapy is well tolerated in patients. Further, the anti-murine antibody response which generally develops in treated humans, surprisingly does not alter significantly the plasma half life of the murine antibody on repeat administration. Thus, high blood levels of antibody can be achieved with sequential injections of high doses to enhance transit of the antibody from intravascular space into the tumor bed and thus provide higher concentrations of the therapeutic antibody to the locus of action.